\\ move one step alongside counterclockwise undulating spiral
move(z) = {
	if (real(z)%2 == imag(z)%2,
			if (imag(z) <= 0, z+1, z-1),
			if (real(z) > 0, z+I,
				real(z)==0 && imag(z) > 0, z+I, z-I)
	);
}

{
	z = 0;
	for (n = 0, 10 081,
		print (n " " norm(z));
		z = move(z);
	);
}

quit